If you have not done so already, visit the WiiLink Patcher releases page and download the correct patcher for your operating system.
Simply download the Windows release (onefile or zip) of your choosing, and open the exe!
Download the macOS release for your Mac (x64 for Intel, arm64 for Apple Silicon), and extract it. Then, launch Terminal. Type in xattr -d com.apple.quarantine with a trailing space, drag the patcher app file into the terminal, and press enter. After this, you can just right click the app file and choose Open!
Download the Linux release for your computer’s architecture and extract it. Then, open a terminal, and use cd to change to the directory you extracted the patcher to. Run chmod +x WiiLinkPatcherGUI to make the patcher executable, and ./WiiLinkPatcherGUI to run it.
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
You can resolve this by running sudo apt install libxcb-cursor-dev.
Express Setup. Follow the steps below:
Custom Setup. Follow the steps below:

Please wait a moment for the patcher to download and patch the files on your device.
If you chose not to store files directly on your SD card / USB device, copy the WAD and apps folder from your chosen output location to the root of your SD card / USB device.
Continue to installing WADs.